I picked on this particular area because all the trees are short and recently planted so the birds were often only at head height, giving me the advantage of not having to look upwards and usually having a distant wood or hedge as the backdrop, rather than sky.
Redpolls are often very static. Once they start to feed on a catkin they can be still for 10 minutes or so, before moving onto the next one. This makes them difficult to spot amongst the branches and catkins. Even if there are a dozen birds in a tree they can go unnoticed at first. Once found though they are a very approachable species. Even with a 400mm lens I could have got close enough today.